Question 1

Which of the following best describes the primary function of the lymphatic system?

Accepted Answer

Housing immune cells such as B and T lymphocytes and macrophages for immune surveillance

Question 2

A patient develops endocarditis after dental surgery. Which organism is most likely responsible, and what is the mechanism?

Accepted Answer

Streptococcus mutans; entry into bloodstream and infection of pre-existing heart lesions

Question 3

Sepsis is a life-threatening condition. Which of the following best explains why sepsis can lead to septic shock?

Accepted Answer

Bacterial toxins cause a sudden decrease in blood pressure due to systemic inflammation

Question 4

Pseudomonas aeruginosa is an opportunistic pathogen. Which characteristic makes it particularly dangerous in hospital settings?

Accepted Answer

It is resistant to many antimicrobials and disinfectants, making infections difficult to treat and prevent

Question 5

Yersinia pestis, the causative agent of plague, can survive inside phagocytic cells. What is the clinical significance of this ability?

Accepted Answer

It allows the bacterium to evade the immune system and spread through the lymphatic system, causing bubonic plague

Question 6

Which of the following is a distinguishing feature of pneumonic plague compared to bubonic plague?

Accepted Answer

Pneumonic plague is transmitted by respiratory droplets and is nearly 100% fatal within three days

Question 7

Epstein-Barr Virus (EBV) primarily targets which type of cell, and what is the consequence for the immune system?

Accepted Answer

B cells; weakened antibody-mediated immunity due to cytotoxic T cell destruction of infected B cells

Question 8

A patient presents with high fever, vomiting blood, and profuse bleeding from internal and external openings. Which disease is most likely, and what is its natural host?

Accepted Answer

Ebola hemorrhagic fever; fruit bat

Question 9

Malaria is characterized by a cyclical fever. What is the underlying cause of this fever cycle?

Accepted Answer

Release of a new generation of Plasmodium from red blood cells every 2-3 days

Question 10

Which of the following best explains why broad-spectrum antibiotics are often used as a preventative measure after dental surgery?

Accepted Answer

To prevent infection by Streptococcus mutans entering the bloodstream and causing endocarditis

Question 11

A hospital patient develops sepsis after a urinary tract infection. Which prevention strategy is most effective in reducing sepsis risk?

Accepted Answer

Diagnosing and treating local infections promptly and maintaining strict infection control in hospital settings

Question 12

Which equation best represents the relationship between the number of infected individuals ($$I$$), the transmission rate ($$\beta$$), and the susceptible population ($$S) in a $$simple epidemic model?

Accepted Answer

$$\frac{dI}{dt} = \beta S I$$

Question 13

Which of the following is a plausible reason for the high mortality rate in Ebola hemorrhagic fever?

Accepted Answer

The virus causes multiple organ failure due to widespread internal and external bleeding

Question 14

Which of the following best describes the mechanism by which Plasmodium species cause anemia in malaria?

Accepted Answer

Destruction of red blood cells during the parasite's life cycle

Question 15

A patient with a burn wound develops a blue-green pigment at the site. Which organism is most likely responsible, and what is a key feature of its pathogenicity?

Accepted Answer

Pseudomonas aeruginosa; production of endotoxin that can cause septic shock

Question 16

Which of the following is a real-world example of nosocomial infection leading to sepsis?

Accepted Answer

A patient develops sepsis after a surgical wound becomes infected with Klebsiella pneumoniae

Question 17

Which of the following best explains why antibiotic resistance is a major concern in treating sepsis?

Accepted Answer

Resistant bacteria such as KPC can survive antibiotic treatment, making infections harder to control and increasing mortality

Question 18

Which of the following is a plausible multi-step scenario for the development of endocarditis?

Accepted Answer

A patient with a congenital heart defect undergoes dental surgery, Streptococcus mutans enters the bloodstream, infects pre-existing heart lesions, and causes fever and tissue damage

Question 19

Which of the following best describes the prevention strategy for Pseudomonas infections in burn patients?

Accepted Answer

Debriding wounds and applying topical antibiotics to prevent colonization by Pseudomonas aeruginosa

Infections of the Blood and Lymphatic System: Microbiology Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards